Write the principle of the following
(a) Zone refining
(b) Froth flaotation process
(c) Chromatography

Explanation

(a) N/A
(b) Froth floatation process: This method is widely used for the concentration of sulphide ores such as,zinc blende (ZnS), copper pyrites `(CuFeS_(2))`, galena (PbS) etc. It is based upon the principle that the surface of sulphide ores is pre-ferentially wetted by oils become lighter and thus, rise to the surface along with froth while the gangue particles which preferentially wetted by water become heavier and thus, settle down at the bottom of the tank.
(c) N/A